The present invention relates, in general, to fluid fittings and, more particularly, to an improved fitting having a low volume crevice. In one embodiment, the fitting includes a coupling body having an inside surface for engaging an outside surface of a fluid conduit and a shoulder portion for limiting axial insertion of the fluid conduit into the coupling body. The fitting further includes at least one seal formed on the inside surface of the coupling body. The at least one seal includes a proximal seal adjacent the shoulder portion. The fitting also includes a ring annularly disposed on the coupling body urging the at least one seal into the fluid conduit to seal and mechanically connect the coupling body to the fluid conduit. The improved fitting will be described with particular reference to this embodiment, but it is to be appreciated that the improved fitting is also amenable to other like applications.
Various types of fittings have been developed for joining tubes and pipes to other tubes and pipes, or to other fluid apparatus such as pumps, fluid motors, actuation cylinders, etc. For thin walled tubing or pipe, various types of fittings are used which compress against the outside diameter of the tube or pipe to create a seal. One particular type of such a fitting includes a swage ring which is forced over the fitting to compress it radially inwardly against the tube or pipe to create a seal. Generally, this type of fitting has one or more circumferential teeth or ridges on its inside diameter which, when compressed inwardly by a swage ring, engage the outside diameter of the tube or pipe to create one or more leak-tight mechanical connections or joints between the tube or pipe and the fitting. This engagement of the sealing teeth of the fitting with the tube or pipe causes the pipe to be deformed radially inwardly, with the coupling body of the fitting located externally about the tube or pipe.
Examples of such mechanically attached fittings are provided in U.S. Pat. Nos. 4,482,174; 5,110,163; 5,114,191; and 6,692,040. One example installation tool employable for attaching these types of fittings to a tube or pipe is described in U.S. Pat. No. 5,305,510. All the teachings and substance of these patents are hereby expressly incorporated by reference into the present application.
The fittings described above are suitable for a variety of applications. However, in some applications, these fittings allow residual amounts of whatever passes through the fitting to accumulate in the fitting and/or between the fitting and the tube or pipe to which the fitting is attached. More particularly, a fluid or other substance may undesirably accumulate between the end of the pipe and the fitting body, as well as between an outside surface of the pipe and the fitting, extending axially to the first seal. Reducing this amount of space between the pipe and the fitting could desirably lessen the area in which residual amounts may accumulate. Thus, any improvement to the fitting that would lessen the area in which residue may gather is deemed desirable.